Re: is it a bug?!please help.
- To: mathgroup at smc.vnet.net
- Subject: [mg107252] Re: is it a bug?!please help.
- From: "Nasser M. Abbasi" <nma at 12000.org>
- Date: Sat, 6 Feb 2010 03:29:55 -0500 (EST)
- References: <hkgl3d$6t8$1@smc.vnet.net>
"olfa" <olfa.mraihi at yahoo.fr> wrote in message news:hkgl3d$6t8$1 at smc.vnet.net... > Hello mathematica community, > for Sum[k[i], {i, 1, n}] + Sum[k[i], {i, n + 1, m}] > why mathematica cannot give as output Sum[k[i],{i,1,m]]?! > please help. > My guess is that "+" is currently not defined for Sum while it is in its symbolic form? But it works ok when one plugs in some actual integer values for n and m: Clear[s1,s2,k,n,m,i] s1=Sum[k[i],{i,1,n}] s2=Sum[k[i],{i,n+1,m}] s1+s2/.{n->5,m->7} k[1]+k[2]+k[3]+k[4]+k[5]+k[6]+k[7] --Nasser